MWPCA Procedure

RPCA Statement

  • RPCA <options>;

If you specify the ROBUST option in the PROC MWPCA statement, then you can use this statement to specify the following RPCA options:

FIXEDMU

uses a fixed value for in each iteration of RPCA when METHOD=APG. Otherwise, is updated dynamically in each iteration.

LAMBDA=number

specifies a value for , where number is a positive real number. The default value is computed by , where n is the greater of the number of observations and the number of variables in the input data set. This parameter affects the sparsity of the sparse matrix. For more information, see Candès et al. (2011).

LAMBDAWEIGHT=number

specifies the value of . The final value of the that is used in the RPCA algorithm is calculated by multiplying by . You can use this value to control the sparsity of the sparse matrix. For more information about the sparse matrix in RPCA, see Chapter 30, RPCA Procedure.

By default, LAMBDAWEIGHT=1.

MAXITER=number

specifies the maximum number of iterations before the RPCA algorithm stops, where number is a positive integer. By default, MAXITER=1000.

METHOD=ALM | APG

specifies the method to perform RPCA. You can specify the following values:

ALM

specifies the augmented Lagrange multiplier method.

APG

specifies the accelerated proximal gradient method.

For more information about each method, see the section Details: RPCA Procedure.

By default, METHOD=ALM.

MU=number

specifies an initial value of when METHOD=APG. By default, MU=.

TOLERANCE=number

specifies the convergence criterion for the RPCA algorithm on each window. By default, TOLERANCE=.

Last updated: October 13, 2026